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Abstract:

The present invention proposes novel salt compounds for use in the
diagnosis or therapy of a patient as well as drugs, medical products,
diagnostic compositions or blood products containing a salt compound
according to the invention. The salt compounds according to the invention
comprise the cation of a metabolisable basic amino acid and the anion of
a metabolisable carboxylic acid or an anion of carbonic acid. Those salt
compounds therefore have the advantage that they are fully metabolisable
and thus do not adversely affect the electrolyte balance or the acid-base
balance of the patient. The proposed salt compounds are particularly
suitable for the therapy of the liquid and electrolyte balance of a
patient but also for adjusting the pH-value in a biological or medical
sample, for adjusting the osmolality in infusion solutions, as buffer
substances, for feeding biocarbonate to a patient and for inhibiting
blood coagulation for example in a patient, in extracorporeal blood
treatment in the diagnostic determination of blood coagulation or in the
production, storage and preparation of blood products.

Claims:

1-13. (canceled)

14. A preparation for the inhibition of blood coagulation, wherein the
preparation is an aqueous solution of at least one salt compound
comprising: a) the cation of the basic amino acid lycine or arginine, and
b) the anion of citric acid, characterized in that the basic amino acid
is selected from the proteinogenic amino acids L-lysine or L-arginine and
the aqueous solution in comparison with human blood plasma is isotonic,
isonatriaemic, isokaliaemic and isohydric.

15. A preparation according to claim 14, characterized in that the at
least one salt compound is selected from mono-lycine citrate,
mono-arginine citrate, di-lycine citrate, di-arginine citrate, tri-lycine
citrate and tri-arginine citrate.

16. A preparation according to claim 14, characterized in that at least
one salt compound is di-arginine-mono-lycine citrate (Arg2-Lys
citrate).

17. A preparation according to claim 14, characterized in that the base
excess (BE) of a patient after administration of the preparation is
0.+-.10 mmol/l.

18. A preparation according to claim 14, characterized in that the
potential base excess (BEpot) after metabolization of a patient after
administration of the preparation is 0.+-.10 mmol/l.

19. A preparation according to claim 14, characterized in that the
preparation is used as an agent for inhibiting blood coagulation in the
therapeutic reduction in blood coagulation in a patient, in the
therapeutic treatment of a patient by means of a method of extracorporeal
blood treatment, in diagnostic determination of blood coagulation in
vitro or in another diagnostic in vitro method, in which temporarily
uncoagulatable blood is produced by calcium being complexed with citrate
ions, wherein the anion of the salt compound is respectively citrate.

20. A preparation according to claim 14, characterized in that the use of
the preparation for the inhibition of blood coagulation is effected in
the therapeutic treatment of a patient by means of an extracorporeal
blood treatment method, wherein the extracorporeal blood treatment method
is selected from the following: treatment with a heart-and-lung machine
(HLM), extracorporeal membrane oxygenation (ECMO), continuous renal
replacement therapy (CRRT), haemofiltration (CVVH), haemodialysis
(CVVHD), haemodiafiltration (CVVHDF) and intermittent renal replacement
therapy or intermittent haemodialysis (IHD).

21. A preparation according to claim 14, characterized in that the
preparation is used for the inhibition of blood coagulation in the
production, storage and preparation of blood products, wherein the anion
of the salt compound is respectively citrate.

22. A preparation according to claim 14, characterized in that the
patient is a human being or a mammal.

23. A preparation according to claim 14, characterized in that the
preparation is a drug preparation, a medical product, a diagnostic
composition for in vitro or in vivo diagnostics or a blood product.

24. A preparation according to claim 14, characterized in that the
preparation is an aqueous solution suitable for intravenous
administration to a patient.

25. A preparation according to claim 14, characterized in that the
preparation additionally includes at least one pharmaceutically
compatible carrier, additive or diluent substance.

26. A preparation according to claim 14, characterized in that the at
least one salt compound is L-arginine citrate and the preparation is
adapted to human plasma with L-arginine citrate as follows: isotonic with
an osmolality of 288.+-.10 mosmol/kg H2O, isonatriaemic with
142.+-.10 mmol/l sodium, isokaliaemic with 4.5.+-.2 mmol/l potassium,
isohydric in vitro with a base excess (BE) of 0.+-.10 mmol/l and in vivo
with a potential base excess (BEpot) of 0.+-.10 mmol/l.

Description:

[0001] The present invention concerns salt compounds for use in diagnosis
or therapy of a patient as well as drugs, medicinal products, diagnostic
compositions or blood products which contain a salt compound according to
the present invention.

[0002] In any feed of relatively large amounts of fluid into the body of a
patient attention is to be paid to using an electrolyte solution which is
as balanced as possible and which has the physiological electrolyte
pattern of the plasma with sodium, potassium, calcium and magnesium as
well as chloride and the contributions thereof to osmolality as well as a
physiological acid-base status with bicarbonate or alternatively other
suitable anions. Therefore infusion of a solution balanced in that way
cannot cause any therapeutic error--except in respect of volume--.
Therefore an object of the present invention is to provide salt compounds
which are particularly well suited to the production of electrolyte
solutions which are as balanced as possible.

[0003] On the other hand there are obviously also forms of fluid therapy,
in which operation is implemented other than with physiologically
composed solutions in order to correct a state differing from the ideal
state or preventively to maintain the physiological conditions in
opposition to a circumstance or agent acting in a different direction.
What is decisive in the specified cases is that in any administration of
solutions containing electrolytes or of solutions which can influence the
electrolyte balance, that is effected in such a way that overall it is
not just the desired electrolyte balance but also the desired acid-base
equilibrium and the ideal osmolality that are achieved, and therefore an
object of the present invention is also to provide salt compounds
suitable for that purpose.

[0004] Theoretically ammonium bicarbonate (also ammonium hydrogen
carbonate or NH4HCO3) would be suitable for elimination of the
two gaseous metabolism end products CO2 and NH3 and in addition
as a physiological buffer substance in the body fluid balance. Ammonium
bicarbonate with its pH-value of 7.4-7.6 (depending on the respective ion
strength) has ideal properties as a physiological buffer substance. The
pH-value of ammonium bicarbonate results from the pK-values of the two
hydrated subunits and the anions resulting therefrom HCO3.sup.- (pK
6.1) and NH4.sup.+ (pK 9.0).

[0005] In the neutral pH-range of 6 to 8 and in particular in the
physiological pH-range of 7.4±0.4 there are scarcely buffer substances
which could be therapeutically used. Synthetic buffers which are used in
particular in laboratory biology, in the relevant pH-range, are for
example Hepes with an almost ideal pK of 7.35 and Tris with a pK of 8.2.
Hepes however is not used on the human being. Only Tris--for the therapy
of an acidosis--and arginine hydrochloride--for the therapy of an
alkalosis--are permitted as medicaments for use on human beings.

[0006] Therefore an object of the present invention is to provide salt
compounds which are suitable for the therapy of the fluid balance of a
patient and in respect of the use of which the electrolyte balance, the
acid-base equilibrium and/or the osmolality can be adjusted in the
desired fashion in the patient to be treated.

[0007] Besides targetedly influencing the fluid balance such as for
example in infusion therapy there are a series of therapeutic
interventions which have an unwanted influence on the fluid balance. For
example in the machine production of blood plasma or blood cell
concentrates (plasma- or cytapheresis) relatively large amounts of
citrate are frequently added to the blood flow passed extracorporeally
through the apparatus for reducing the blood coagulation tendency. The
citrate is usually supplied in the form of sodium citrate plus citric
acid, for example in the form of ACD-A.

[0008] ACD-A (acid citrate dextrose type A) is a solution of citric acid,
sodium citrate and D-glucose in water. ACD-A prevents coagulation of the
blood, in which the Ca2+ ions which are essential for blood
coagulation are complexed (bound). ACD-A is traditionally used in the
production and storage of blood products for coagulation inhibition.

[0009] ACD-A is a strongly hypotonic solution both in vitro (in the
laboratory) and also in vivo (in the patient). In diagnostics in vitro
ACD-A produces in the blood an acidosis with a BE (base excess; see
hereinafter) of -13.8 mmol/l after dilution of 1:10 (9 parts of blood+1
part of solution). When used for blood coagulation inhibition in
conjunction with the extracorporeal blood treatment ACD-A can produce a
strongly positive BEpot (potential base excess; see hereinafter) in the
patient, in accordance with how much of the constituents of the ACD-A
solution occur in the patient. In addition ACD-A (Na concentration of
Na3 citrate: of 224.4 mmol/l) in comparison with the blood plasma
(Na concentration: 142 mmol/l) is a strongly hypernatriaemic but
potassium-free solution (K-concentration of the blood plasma: 4.5
mmol/l).

[0010] Although the attempt is made to remove again the sodium citrate
introduced into the patient blood by way of the ACD-A solution prior to
returning the blood into the body of the patient, it is to be assumed
that a not inconsiderable amount of the sodium citrate used remains in
the patient blood and can thus lead to impairment of the physiologically
normal electrolyte and acid-base status of the patient.

[0011] Therefore an object of the present invention is also to provide
salt compounds with which blood coagulation can be reduced for example in
the therapeutic treatment of a patient by means of a method of
extracorporeal blood treatment, without detrimentally influencing the
electrolyte and/or the acid-base balance of the patient. In addition
those salt compounds are also intended to be capable of serving as an
agent for inhibiting blood coagulation for the purposes of targeted
therapeutic reduction of blood coagulation in a patient. In addition the
salt compounds are also intended to be capable of use in diagnostic
determination of blood coagulation or in a diagnostic method in which
temporarily uncoagulatable blood is produced, by calcium being complexed
(bound) with citrate ions (calcium-free blood) and then involving
avoidance of the citrate effect (for example by CaCl2 addition) with
free Ca ions.

[0012] According to the invention the object of the present invention is
attained in that a salt solution for use in the diagnosis or therapy of a
patient is produced, wherein said salt compound is characterised in that
it comprises the cation of a metabolisable basic amino acid and either
the anion of a metabolisable carboxylic acid or an anion of carbonic
acid.

[0013] `Salts` are compounds comprising an anion and a cation. In an
organic salt at least one anion or cation is an organic compound. In the
case of the present invention at least the cation, namely the basic amino
acid, is an organic compound. In the embodiments of the invention in
which the anion is a metabolisable carboxylic acid both the cation and
also the anion are organic compounds.

[0014] `Amino acids` are organic compounds comprising an amino group
(--NH2), a carboxyl group (--COOH), a hydrogen atom and an organic
side chain R which are bound to a C atom which is identified as an
α carbon atom. Amino acids are of the following general formula:

00

##STR00001##

[0015] The protonated amino group can react as an acid and the carboxyl
group as a base. At a given pH-value the amino acid is present
substantially in the form of a zwitterion and is neutral in external
behaviour. That pH-value is referred to as the isoelectric point
(pHIP).

[0016] In `basic` amino acids the side chain R contains basic functional
groups, preferably amino groups, which can be easily protonated. The side
chains of basic amino acids can react with acid and involve a salt bond,
the salt then comprises the singly positively charged amino acid cation
and the acid anion.

[0017] The basic amino acids have two basic pKS-values and one acid
pKS-value. The isoelectric point in basic amino acids is in the
basic pH-range between the two basic pKS-values pKS2 and
pKS3 (pHIP>7).

[0018] The basic `side chain R` can be a straight- or branched-chain
aliphatic, aliphatic-aromatic, aromatic or heterocyclic residue which has
at least one basic functional group, preferably an amino group.
Preferably the basic side chain R is a straight- or branched-chain
aliphatic C1-C8 alkyl residue, still more preferably a
straight- or branched-chain aliphatic C1-C4 alkyl residue.

[0019] The `cation` of a basic amino acid is the ion which in total is
positively charged externally of the respective basic amino acid.
Preferably this involves an ion of the respective basic amino acid, that
in total is singly positively charged externally. In an alternative
embodiment this involves an ion of the respective basic amino acid, that
is in total doubly positively charged externally.

[0020] The `metabolism` is the totality of the chemical building-up
(anabolism) and breaking-down reactions (catabolism) which occur in
living beings in connection with the processes for maintaining life, for
example nutrient absorption, energy generation, growth, motion. In
connection with the present invention those substances which can be
enzymatically metabolised by the body of the patient are referred to as
`metabolisable`. In other words those substances are substrates which can
be chemically converted into other substances by body-specific enzymes of
the metabolic system of the patient.

[0021] Accordingly the cations of the salt compounds according to the
invention are basic amino acids which can be chemically converted into
other substances by body-specific enzymes of the metabolic system of the
patient.

[0022] Preferably the basic amino acids in accordance with the present
invention are those amino acids which are intermediate products or end
products in the metabolic system of the patient in the healthy state.
They can be either proteinogenic or non-proteinogenic amino acids.

[0023] `Non-proteinogenic` amino acids in accordance with this invention
are those basic amino acids which would admittedly occur in the metabolic
system of the patient in the healthy state but which are not present as
building blocks of the proteins of the patient. Examples of such
non-proteinogenic basic amino acids are ornithine and citrulline (both
metabolic intermediate products in the urea cycle).

[0024] Preferably the non-proteinogenic basic amino acids according to the
invention do not have any pharmacological action of their own and they
are thus pharmacologically inert.

[0025] In another embodiment the basic amino acids are proteinogenic amino
acids, wherein the term `proteinogenic` amino acids is used to denote all
amino acids which are the building blocks of the proteins of the patient,
in which case the proteinogenic amino acids always involve L-amino acids.

[0026] The proteinogenic basic amino acids known at the present time
include L-lysine, L-arginine and L-histidine. In a preferred embodiment
either L-lysine or L-arginine are used as the metabolisable basic amino
acid. In an alternative embodiment the D-enantiomers of the proteinogenic
amino acids are used as the basic amino acids.

[0027] The anion of the salt compound according to the invention is the
anion of a metabolisable carboxylic acid or an anion of carbonic acid.

[0028] The term `metabolisable` is used in connection with the carboxylic
acid of the present invention in the same sense as was defined
hereinbefore for the metabolisable amino acid. Accordingly the anions of
the salt compounds according to the invention are carboxylic acids which
can be chemically converted into other substances by body-specific
enzymes of the metabolic system of the patient.

[0029] Preferably the carboxylic acid in accordance with the present
invention involves those carboxylic acids which are intermediate products
or end products in the metabolic system of the patient in the healthy
state such as for example lactic acid, gluconic acid and tartaric acid.
Further examples of carboxylic acids which are intermediate products or
end products in the metabolic system of the patient in the healthy state
are the carboxylic acids which are involved in the citrate cycle such as
for example acetic acid, citric acid, isocitric acid,
α-ketoglutaric acid, succinic acid, fumaric acid, malic acid and
oxalic acid.

[0030] In an alternative embodiment of the salt compounds according to the
invention the anion is an anion of carbonic acid.

[0031] Carbonic acid (H2CO3) is a two-proton acid whose salts
are called carbonates (anion: CO32-) or hydrogen carbonate
(anion: HCO3.sup.-). Accordingly the anion of this embodiment can be
the carbonate anion or the hydrogen carbonate anion.

[0032] The term `anion` of a metabolisable carboxylic acid or an `anion`
of carbonic acid is the ion of the respective deprotonated carboxylic
acid or carbonic acid, which in total is negatively charged externally.
Preferably this involves an ion which in total is singly negatively
charged externally (for example: HCO3.sup.-) of the respective
deprotonated carboxylic or carbonic acid. In an alternative embodiment
this involves an ion which in total is doubly negatively charged
externally (for example: CO32-) of the respective deprotonated
carboxylic or carbonic acid.

[0035] In the case of two basic amino acids the two amino acids can be
identical or can differ from each other. In the case of succinic acid, in
an embodiment for example 1 mol of succinic acid can be combined with 1
mol of arginine (Arg succinic) or 1 mol of succinic acid can be combined
with 2 mols of arginine (Arg2 succinate) but also 1 mol of succinic
acid with 1 mol of arginine and 1 mol of lysine (Arg Lys succinate). The
present invention therefore embraces in particular all combinations of
cations of two different metabolisable basic amino acids with the anions
of a two-protonic or three-protonic metabolisable carboxylic acid or the
anions of the carbonic acid, the listing of which is dispensed with here
only because those combinations are in any case already directly clearly
and unambiguously disclosed to the man skilled in the art by the
information set forth herein.

[0036] In the case of three-protonic acids they can correspondingly form
in one, two or three positions salt compounds with the same basic amino
acid or with different basic amino acids. For example the present
invention embraces salt compounds of 1 mol of citric acid and 1 mol of
arginine (Arg citrate), salt compounds of 1 mol of citric acid and 2 mols
of aginine (Arg2 citrate) and salt compounds of 1 mol of citric acid
and 3 mols of aginine (Arg3-citrate). The present invention
therefore embraces by way of example and without limitation thereto in
particular also the following salt compounds: tri-lysine citrate,
tri-lysine isocitrate, tri-arginine citrate and tri-arginine isocitrate.

[0037] As already mentioned the invention also embraces those salt
compounds in which three-protonic acids are combined with different basic
amino acids. Thus the invention also embraces for example salt compounds
comprising 1 mol of citric acid in combination with 2 mots of aginine and
1 mol of lysine (Arg2-Lys citrate). The present invention therefore
embraces in particular all combinations of cations of three different
metabolisable basic amino acids with the anions of a three-protonic
metabolisable carboxylic acid, the listing of which is dispensed with
here only because those combinations are in any case already directly
clearly and unambiguously disclosed to the man skilled in the art by the
information set forth herein.

[0038] The salt compounds of the present invention have the advantage that
they can be completely metabolised, that is to say even upon
administration thereof in a large amount into the blood circulation or
upon use thereof in a large amount in connection with blood products the
above-mentioned disadvantages of the conventional salt compounds used for
those purposes do not occur. As the constituents of the salt compounds
according to the invention are completely metabolisable they can be
readily integrated into the metabolic system of the patient and
metabolised by way thereof without any fear of permanently influencing
the electrolyte balance and/or the acid-base balance of the patient.

[0039] Accordingly the salt compounds according to the invention can
advantageously be employed for use in diagnostics or therapy of a
patient.

[0040] An example of therapeutic use of the salt compounds according to
the invention is infusion therapy, by intravenous administration of
relatively large amounts of fluid for the purposes of increasing the
intravasal fluid volume and/or the extracellular fluid volume in volume
replacement, fluid supply and/or electrolyte or osmotherapy.

[0041] In a preferred embodiment the salt compound according to the
invention can be used as an agent for adjusting the base excess (BE) or
the potential base excess (BEpot) in a patient (either acidifying or
alkalising).

[0042] The `BE` (base excess: [mmol/l]) describes the action that a
substance or a mixture of substances has when the substance or the
mixture is added to a blood sample in vitro or in vivo. A negative
BE-value means that the added substance or mixture causes acidification
of the blood. A positive BE-value means that the added substance or
mixture leads to alkalisation of the blood. The potential base excess
(Bepot) additionally describes the effect in a patient in vivo after the
added substance or mixture was potentially metabolised in the patient.

[0043] The results shown in Table III of Example No 3 show that Na3
citrate permits a BE of 0 mmol/l. Na3 citrate originally therefore
does not have any influence on the pH-value or the BE of the blood. It
will be noted however that Na3 citrate has a relatively great
influence on the BEpot of the patient and the sodium loading is
considerable. In the case of pure citric acid there is no sodium loading
on the patient. It will be noted however that citric acid leads to a
negative even if reversible BE of the patient as soon as it has been
metabolised.

[0044] The advantage of the salt compound according to the invention is
that the BE of the patient is not influenced by the presence thereof.
Preferably the phase deviation (BE) of the patient is 0±10 mmol/l
after administration of the substance. In addition the potential base
deviation (BEpot) after metabolisation of the substance is preferably
only 0±10 mmol/l.

[0045] In a further embodiment the salt compound according to the
invention is used for adjusting the pH-value in a biological or medicinal
sample. In this case too the advantage is that the BE of the sample is
not influenced thereby. For example 100 mmol/l of Arg acetate (pK 4.6)
has a buffer capacity β of only 7.0 mmol/l/pH. Arg acetate however
can buffer towards both sides because β increases towards both
sides. If therefore a pH-value of 7.4 is to be set only 7.3 mmol/l/NaOH
has to be added.

[0046] In still a further embodiment of the invention the salt compound is
used as a buffer substance. It is to be noted in this respect that the
buffer capacity β of the salt compound is correspondingly greater,
the higher the uppermost (most alkaline) pK of the acid is and the more
arginine or lysine is present (mono-, di- and tri-amino acid salts).
Preferred salt compounds in this connection are therefore those whose
uppermost (most alkaline) pK-value>0, still more preferably >12. In
addition those salt compounds are preferred, in which more than 1 mol
basic amino acid per 1 mol carboxylic acid are combined (for example
Arg2 succinate). Still more preferred are those salt compounds in
which more than 2 mols basic amino acid per 1 mol carboxylic acid are
combined (for example Arg3 citrate). Particularly preferred are
those salt compounds in which 2 mols (for example Arg2 succinate) or
3 mols (for example Arg3 citrate) basic amino acid per 1 mole
carboxylic acid are combined.

[0047] In a further embodiment of the invention the salt compound is used
for adjusting osmolality in infusion solutions. That has the advantage
that no inorganic electrolytes which could negatively influence the
electrolyte balance of the patient have to be added to the infusion
solution. The salt compounds according to the invention act here
so-to-speak as `osmolalic place holders`, that is to say in an infusion
solution the osmolality can be adjusted as desired without an influence
on the electrolyte composition.

[0048] In still a further embodiment the salt compounds according to the
invention are used for the feed of bicarbonate anions in the patient in
vivo. The advantage is that here too the addition of possibly detrimental
inorganic electrolytes can be dispensed with. In addition there is in
that way also the possibility of avoiding the disadvantages of inorganic
bicarbonate (CO2 as volatile base).

[0049] In still a further embodiment the salt compounds according to the
invention are used for the preparation of bicarbonate in a biological or
medical sample.

[0050] In another embodiment the salt compounds according to the invention
are used for artificial (parenteral) nutrition because as a mixture of
amino acid and possibly organic carboxylic acid they represent pH-neutral
energy carriers (for example 10 g of Arg acetate provides 35.4 kcal;
arginine=4 kcal/g and acetate=3.5 kcal/g).

[0051] In an alternative embodiment the salt compound according to the
invention serves for use as an agent for inhibiting blood coagulation.
For example the salt compound can be used in the therapeutic reduction in
blood coagulation in a patient. For that purpose the salt compounds
according to the invention can be intravenously administered to the
patient in a suitable dosage in the form of an appropriate drug
preparation.

[0052] In an alternative embodiment the salt compound according to the
invention serves for inhibiting blood coagulation in the therapeutic
treatment of a patient by means of a method of extracorporeal blood
treatment by the salt compound according to the invention being added to
the patient blood to be treated. Examples of methods of extracorporeal
blood treatment are treatments with a heart-and-lung machine (HLM),
extracorporeal membrane oxygenation (ECMO), continuous renal replacement
therapy (CRRT), like for example haemofiltration (CVVH), haemodialysis
(CVVHD), haemodiafiltration (CVVHDF) and intermittent renal replacement
therapy or intermittent haemodialysis (IHD). In those methods the salt
compounds according to the invention can be extracorporeally added to the
patient blood in an appropriate dosage in the form of a suitable
preparation, wherein the advantage of the salt compounds according to the
invention is in particular that the salt compounds do not have to be
completely removed from the blood again prior to returning the
extracorporeally treated blood as the compounds do not have any unwanted
influence on the electrolyte and acid-base balance of the patient and can
be completely metabolised by the patient metabolic system: non-removed
proportions which remain in the patient--in contrast to the conventional
citrate--do not alter the BE, the BEpot, the levels of electrolyte
concentration or the osmolality of the patient, independently of dilution
in the patient blood.

[0053] The present invention also embraces the use of the salt compound
according to the invention as a diagnostic agent for inhibiting blood
coagulation in an in vitro method of blood coagulation diagnostics or in
another diagnostic in vitro method in particular when in the method
temporarily uncoagulatable blood is produced by calcium being complexed
(bound) with citrate ions (calcium-free blood), then involving avoidance
of the citrate effect with free Ca ions (for example by CaCl2
addition). In conjunction with those embodiments the salt compounds
according to the invention are added to the sample in a suitable dosage
in the form of an appropriate diagnostic preparation.

[0054] In the course of a blood coagulation diagnostic process, beginning
with taking the blood (pre-analysis), no changes should be made to the
pH-value of the sample to be investigated as any pH-change must influence
the diagnostic result (Zander: DE 10 2008 022 884, WO 2009/135785 and EP
09 742 003). In principle a pure citrate solution is suitable for that
purpose, which because of its 3 pK-values at the blood pH-value of about
7.40 has practically no buffer capacity. Such a solution however has a
pH-value of about 8.5. If in contrast solutions with an addition of
citric acid are used identified as buffered solutions, the pH-values of
the blood sample are markedly altered.

[0055] Thus the requirement for a citrate solution should be that the BE
of the solution must be 0 mmol/l so that in use of that solution no
change in pH-value in the blood-solution mixture occurs. The requirement
for a BE of 0 mmol/l can additionally be implemented with bicarbonate (24
mmol/l), but only when there is no citric acid at the same time because
bicarbonate remains stable only at the pH-value of 7-9. An embodiment is
described hereinafter in Example 5a).

[0056] In a further embodiment of the invention the salt compounds
according to the invention are used for the inhibition of blood
coagulation in the production, storage and processing (for example
plasmapheresis and cytapheresis) of blood products. In these embodiments
the salt compounds according to the invention are added to the respective
blood product in the production, storage and processing thereof in a
dosage suitable for inhibiting blood coagulation.

[0057] In the aforementioned embodiments in which the salt compound
according to the invention is used as an agent for inhibiting blood
coagulation the anion of the salt compound according to the invention is
the citrate anion in each case.

[0058] In a preferred embodiment the salt compound according to the
invention is used in the form of a preparation which in comparison with
the human blood plasma is isotonic, isonatriaemic, isokaliaemic and/or
isohydric. An example of such an embodiment is a citrate-bearing agent
for coagulation inhibition, wherein the composition is adapted to the
human plasma with arginine citrate: isotonic (osmolality 288±10
mosmol/kg H2O), isonatriaemic (sodium 142±10 mmol/l),
isokaliaemic (potassium 4.5±2 mmol/l), isohydric in vitro (base excess
BE 0±10 mmol/l) and in vivo (potential base excess 0±10 mmol/l).
Embodiments are described hereinafter in Example 5a) and b). Selectively
a solution with an alkalising effect in vivo can also be adopted
(potential base excess+5 to +50 mmol/l).

[0059] The salt compounds of the present invention can be used in
connection with the diagnosis and therapy of all living beings who have a
blood circulation system comparable to a human being. Preferably the
patient is a mammal. Still more preferably the patient is a human being.

[0060] The present invention also embraces preparations which include at
least one salt compound according to the invention and in addition at
least one pharmaceutical compatible carrier, additive or diluent
substance. The carrier, additive or diluent substances which are
considered in connection with the aforementioned applications are
well-known to the man skilled in the art and their respective suitability
for the given purposes of the present invention and the amounts used in
that respect depend on the specific problem of the especial state to be
treated or diagnosed in the context of the present invention and the
overall constitution of the patient.

[0061] Preferably the preparations which include at least one salt
compound according to the invention involve aqueous solutions of at least
one salt compound according to the invention. Such aqueous solutions of
the salt compound or compounds according to the invention which are
suitable for intravenous administration to a patient are particularly
preferred.

[0062] In an embodiment the preparation involves a drug preparation for
reducing blood coagulation in a patient. In another embodiment the
preparation is a preparation or a medicinal product for inhibiting blood
coagulation in the therapeutic treatment of a patient by means of an
extracorporeal blood treatment method. In still another embodiment the
preparation is an additive to a blood product. In a further embodiment
the preparation is a preparation or diagnostic composition for inhibiting
blood coagulation in blood coagulation diagnostics or in another
diagnostic method in which uncoagulatable blood is investigated. In
further embodiments the preparation is an infusion solution, a diagnostic
or therapeutic buffer solution or a solution for adjusting the pH-value
(for example in a biological sample).

[0063] The term `drug` in connection with the present invention embraces
those substances or preparations of substances which are intended for use
in or on the human or animal body and are intended as agents with
properties for healing or relieving or for preventing human or animal
diseases or diseased complaints or which can be used in or on the human
or animal body or administered to a human being or an animal in order
either to restore, correct or influence the physiological functions by a
pharmacological, immunological or metabolic effect or to produce a
medical diagnosis.

[0064] The term `drug` in connection with the present invention however
does not embrace substances or preparations of substances which fall
within the definition of the term `medicinal product`.

[0065] The term `medicinal product` in connection with the present
invention embraces all substances or mixtures of substances which are
intended for use on the patient for detecting, preventing, monitoring,
treating or alleviating diseases, detecting, monitoring, treating,
alleviating or compensating for injuries or disabilities or
investigating, replacing or changing a physiological process, and the
appropriate main action thereof is achieved in or on the human body
neither by pharmacological or immunological means nor metabolically, the
action of which however can be assisted by such means or can first be
made possible thereby.

[0066] `Diagnostics`, `diagnostic agent` or `diagnostic compositions` are
used in accordance with the present invention to denote substances or
mixtures of substances which are employed to investigate the state and
the function of the organism of a patient. They also serve for disease
progress monitoring, therapy monitoring and therapy control. Those
substances or mixtures of substances are either used outside the organism
on samples taken from the body of the patient or delivered by the body
(`in vitro diagnostics`) or have to be administered to the patient for
diagnostic purposes (`in vivo diagnostics`).

[0067] `Blood products` in connection with the present invention are blood
constituents obtained from patient blood or complete blood which have
been processed for transmission (transfusion) to a receiver such as for
example erythrocytes concentrate, frozen fresh plasma (FFP), thrombocytes
concentrate, granulocytes concentrate, thrombocytes-rich plasma, stem
cell preparations and albumin.

[0068] For the purposes of the original disclosure it is pointed out that
all features as can be seen by a man skilled in the art from the present
description and the claims, even if they are described in specific terms
only in connection with certain other features, can be combined both
individually and also in any combinations with others of the features or
groups of features disclosed here insofar as that has not been expressly
excluded or technical aspects make such combinations impossible or
meaningless. A comprehensive explicit representation of all conceivable
combinations of features is dispensed with here only for the sake of
brevity and readability of the description.

[0069] It is further pointed out that it is self-evident to the man
skilled in the art that the embodiments given by way of example in the
present application, as set forth for example in the Examples
hereinafter, serve only to set forth by way of example the possible
embodiments of the invention that are reproduced as configurations by way
of example. The man skilled in the art will therefore readily appreciate
that in addition all other embodiments having the features or
combinations of features according to the invention recited in the claims
fall within the scope of protection of the invention. A comprehensive
explicit representation of all conceivable embodiments is also dispensed
with here only for the sake of brevity and readability of the
description.

[0070] FIG. 1 accompanying this application shows:

[0071] a graphic
representation of the results of a test for investigating the influence
of the ACD-A solution which is usual at the present time on the acid-base
balance of patients involving cytapheresis.

EXAMPLES

1. Buffer Properties of the Salt Compounds According to the Invention

[0072] Following Table I sets out examples of salt compounds according to
the invention, specifying the specific buffer properties thereof.

[0075] 3. Titr on 7.4 (mmol/l): how much NaOH is necessary to set a
pH-value of 7.4.

[0076] 4. Arg3 citrate was crystallised once, after quantitative
addition of H2O the initial values of the pH and osmolality were
restored.

[0077] The following conclusions can be drawn from the present data:

[0078] 1. The buffer capacity β is correspondingly greater, the
higher the uppermost (most alkaline) pK of the acid and the more arginine
or lysine (mono-, di-, tri-) is present. That permits a targeted
selection.

[0079] 2. If a physiological pH-value of 7.4 is to be set in a 0.1 molar
solution then the corresponding additives are specified in the column
Titration pH=7.4. It is therefore specified how much NaOH (mmol/l) is to
be added to set that pH-value.

[0080] 3. It is shown for the investigated 0.1 molar solutions that their
buffer capacity turns out to be low when for comparison the β-value
is specified for normal blood (pH 7.2-7.6) at about 72 mmol/l/pH. That
consideration is important when in the case of Arg3 citrate
unbuffered coagulation inhibition is to be produced with a 0.1 molar
solution (100 mmol/l), a solution which is usually diluted in the blood
at 1:10, which then gives a buffer capacity β of only still 1.9
mmol/l/pH (in comparison with 72 mmol/l/pH).

[0081] 4. Although metabolically convertible those substances do not have
any metabolic effect on the acid-base balance. That will be clear from
the following comparisons:

[0094] Although detected in the measurement of a solution the
glucose--including in vitro--is osmotically not effective as it equally
increases the osmolality both in the plasma and also in the Ery water.

[0095] ACD-A is a severely hypotonic solution.

3. Influence of Citric Acid and Sodium Citrates on BE, BEpot and the
Sodium Concentration

[0096] A typical dilution of 1:10 (9 parts of blood+1 part of citrate
solution) affords the following effects for the various citrate forms if
a typical solution with 100 mmol/l were used for coagulation inhibition:

[0097] The results in Table III show that Na3 citrate permits a BE of
0 mmol/l. Na3 citrate therefore originally exerts no influence on
the pH-value or BE of the blood. It will be noted however that Na3
citrate has a very great influence on the BEpot of the patient and the
sodium loading is considerable although at least in vitro that does not
play any part, assuming isotony. In the case of pure citric acid the
sodium loading of the patient goes. It will be noted however that the
citric acid leads to a negative even if reversible BE of the patient as
soon as the citric acid has been metabolised.

4. Influence of the Salt Compounds not According to the Invention on the
Acid-Base Balance

[0100] Stem cell separation by machine was implemented over about 3 hours
using ACD-A. On average all 10 donors received 829 ml of ACD-A which in
the extracellular space of 14.8 l (20% of the mean body weight of 74.1
kg) had to produce a reversible, citric acid-induced negative BE of -7.7
mmol/l (138.3 mmol/l×0.829 l/14.8 l) and a potential,
citrate-induced positive BE of +11.3 mmol/l (200.4 mmol/l×0.829
l/14.8 l). Because of the time characteristic of the metabolism of citric
acid (reversible acidification) and citrate (irreversible alkalisation)
however both effects can differ. As however alkalisation predominates it
is to be reckoned that this will involve positive BE values. FIG. 1 shows
the maximum positive BE values measured in respect of the patients in
comparison with the predicted theoretical BE for a 50-100% citrate
metabolism. Evidently almost all maximum positive BE values are between
the predictions for a 50% and 100% conversion in the patient.

5. Example Compositions

[0101] a) Use in vitro: total-citrate 97.2 mmol/l (for a later dilution of
1:10)

[0102] Firstly citric acid is dissolved in water, then arginine (3-fold
molar) is added. After buffering citric acid vs. arginine has been
awaited, checking of the pH-value is effected, then addition of citrate
or chloride, lastly NaHCO3 (after buffering) so that there are no
free H.sup.+ ions which could expel HCO3, then addition of H2O.

6. Use of the Salt Compounds According to the Invention for the Feed of
Biocarbonate

[0103] If a solution with 48 mmol/l arginine is mixed with 24 mmol/l
acetic acid that gives a mixture respectively comprising 24 mmol/l
arginine and arginine acetate with a pH-value of about 8.6. That pH-value
corresponds to the effective pK value of arginine (ionic strength 160
mmol/l and 37° C.). If that solution is necessarily equilibrated
after infusion in the patient to a pCO2 of about 40 mmHg a maximum
of 24 mmol/l arginine HCO3 will occur. Thus the physiological values
of about 24 mmol/l HCO3 and a pH-value of about 7.4 will occur (for
comparison arginine equilibration with pure CO2 in Table 1).